Du Xiaoyi, Hou Chuanxin, Kimura Hideo, Song Jinyuan, Yang Xiaoyang, Xie Xiubo, Jiang Huiyu, Zhang Xiaoyu, Sun Xueqin, Zhang Yuping, Gao Song, Du Wei
School of Environmental and Material Engineering, Yantai University, No. 30 Qingquan Road, Yantai, Shandong 264005, China.
School of Environmental and Material Engineering, Yantai University, No. 30 Qingquan Road, Yantai, Shandong 264005, China; Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai, Yantai, Shandong 265503, China.
J Colloid Interface Sci. 2024 Nov;673:92-103. doi: 10.1016/j.jcis.2024.06.024. Epub 2024 Jun 9.
Carbon nanofibers (CFs) have been widely applied as electrodes for energy storage devices owing to the features of increased contact area between electrodes and electrolyte, and shortened transmission route of electrons. However, the poor electrochemical activity and severe waste of space hinder their further application as supercapacitors electrodes. In this work, MnO nanoflowers restricted and epitaxial growth in/out carbon nanofibers (MnO/MnO@CF) were prepared as excellent electrode materials for supercapacitors. With the synergistic effect of uniquely designed structure and the introduction of MnO and MnO nanoflowers, the prepared interconnected MnO/MnO@CF electrodes demonstrated satisfactory electrochemical performance. Furthermore, the MnO/MnO@CF//activated carbon (AC) asymmetric supercapacitor offered an outstanding long-term cycle stability. Besides, kinetic analysis of MnO/MnO@CF-90 was conducted and the diffusion-dominated storage mechanism was well-revealed. This concept of "internal and external simultaneous decoration" with different valence states of manganese oxides was proven to improve the electrochemical performance of carbon nanofibers, which could be generalized to the preparation and performance improvement of other fiber-based electrodes.
由于电极与电解质之间的接触面积增加以及电子传输路径缩短等特性，碳纳米纤维（CFs）已被广泛用作储能装置的电极。然而，其较差的电化学活性和严重的空间浪费阻碍了它们作为超级电容器电极的进一步应用。在这项工作中，制备了限制在碳纳米纤维内部和外延生长在碳纳米纤维外部的MnO纳米花（MnO/MnO@CF），作为超级电容器的优异电极材料。通过独特设计结构的协同效应以及MnO和MnO纳米花的引入，所制备的相互连接的MnO/MnO@CF电极表现出令人满意的电化学性能。此外，MnO/MnO@CF//活性炭（AC）不对称超级电容器具有出色的长期循环稳定性。此外，对MnO/MnO@CF-90进行了动力学分析，并很好地揭示了扩散主导的存储机制。这种用不同价态锰氧化物进行“内外同时修饰”的概念被证明可以提高碳纳米纤维的电化学性能，这可以推广到其他基于纤维的电极的制备和性能改进中。
